Fluid storage tanks are used to contain a fluid for a period of time. A fluid may include a gas, a liquid or combinations thereof. Some fluid storage tanks are pressure vessels. Pressure vessels, such as, e.g., gas storage containers and hydraulic accumulators may be used to contain fluids under pressure. It may be desirable to have a pressure vessel with relatively thin walls and low weight. For example, in a vehicle fuel tank, relatively thin walls allow for more efficient use of available space, and relatively low weight allows for movement of the vehicle with greater energy efficiency.